CN-121983204-A - Method and system for evaluating corrosion resistance of composite board based on spectrum analysis

CN121983204ACN 121983204 ACN121983204 ACN 121983204ACN-121983204-A

Abstract

The invention relates to the field of multispectral imaging analysis and industrial automation control, in particular to a method and a system for evaluating corrosion resistance of a composite board based on spectral analysis. The method comprises the steps of configuring a multispectral imaging unit to synchronously acquire data of a first reference wave band, a second reference wave band and a characteristic wave band on the surface of a plate, calculating a nonlinear attenuation factor representing the leveling pressure induced texture by utilizing the logarithmic difference ratio of the reference wave bands, constructing a theoretical reference reflectivity of the characteristic wave band under pure physical texture based on a power law model, eliminating physical texture interference by calculating the logarithmic residual error of an actual measurement value and the theoretical reference reflectivity, and further evaluating the corrosion resistance of the composite plate. According to the invention, by utilizing the optical transmission and absorption characteristics of the metal surface passivation layer, the distinction between physical texture and chemical corrosion is realized, the false alarm problem of traditional optical detection is effectively solved, and the high-precision online corrosion resistance evaluation is realized.

Inventors

HAO BAOGUO
GAO HAIPENG
HAO NING
LEI YUNLONG

Assignees

宝鸡市力合金属复合材料股份有限公司

Dates

Publication Date: 20260505
Application Date: 20260407

Claims (10)

1. The method for evaluating the corrosion resistance of the composite board based on the spectrum analysis is characterized by comprising the following steps of: configuring a multispectral imaging unit, synchronously collecting spectral response data of each detection point on the surface of the plate to be detected in a first reference wave band, a second reference wave band and a characteristic wave band, and preprocessing the spectral response data to obtain reflectivity data of the detection point in the first reference wave band, the second reference wave band and the characteristic wave band; calculating a nonlinear attenuation factor of the detection point by using the logarithmic difference ratio of the reflectivity data of the detection point in the first reference wave band and the second reference wave band; Based on a preset power law model, utilizing the nonlinear attenuation factor and reflectivity data of the detection point in the first reference wave band to construct theoretical reference reflectivity of the detection point in the characteristic wave band under the condition that only physical texture interference exists; And calculating the logarithmic residual error of the reflectivity data of the detection point in the characteristic wave band and the theoretical reference reflectivity, and evaluating the corrosion resistance of the plate to be tested by utilizing a preset threshold based on the logarithmic residual error.
2. The method for evaluating corrosion resistance of a composite board based on spectral analysis according to claim 1, wherein the first reference band and the second reference band are selected from a spectrum interval in which a passivation layer on a metal surface exhibits optical transmission characteristics, and the characteristic band is selected from a spectrum interval in which a passivation layer on a metal surface exhibits optical absorption characteristics.
3. The method for evaluating corrosion resistance of a composite board based on spectral analysis according to claim 1, wherein the preprocessing comprises obtaining dark background noise data and standard whiteboard response data of the multispectral imaging unit, performing radiation correction on the spectral response data by using the dark background noise data and the standard whiteboard response data, and converting the spectral response data into the reflectivity data.
4. The method for evaluating corrosion resistance of a composite plate based on spectral analysis according to claim 1, wherein the nonlinear attenuation factor satisfies the relation: Wherein, the Is the nonlinear attenuation factor; reflectivity data for the first reference band; reflectivity data for the second reference band; a center wavelength value for the first reference band; A center wavelength value for the second reference band; is a very small positive number.
5. The method for evaluating corrosion resistance of a composite plate based on spectral analysis according to claim 1, wherein the theoretical reference reflectivity satisfies a relation: Wherein, the Is the theoretical reference reflectivity; reflectivity data for the first reference band; a central wavelength value of the characteristic wave band; a center wavelength value for the first reference band; Is the nonlinear attenuation factor.
6. The method for evaluating corrosion resistance of a composite plate based on spectral analysis according to claim 1, wherein the logarithmic residual satisfies the relation: Wherein, the Is the log residual; Reflectivity data for the characteristic bands; is the theoretical reference reflectivity; is a very small positive number.
7. The method for evaluating corrosion resistance of a composite board based on spectrum analysis according to claim 1, wherein the preset threshold value is obtained through a physicochemical signal decoupling calibration experiment.
8. The method for evaluating the corrosion resistance of the composite board based on the spectral analysis is characterized by evaluating the corrosion resistance of the board to be tested by utilizing a preset threshold, and concretely comprises the steps of traversing each detection point, comparing the logarithmic residual with the preset threshold, marking the detection point as a normal point when the absolute value of the logarithmic residual is smaller than or equal to the preset threshold, marking the detection point as a suspected defect point when the absolute value of the logarithmic residual is larger than the preset threshold, carrying out connected domain analysis on all the suspected defect points, counting the number of the suspected defect points contained in each independent connected domain and converting the number into a physical defect area, and judging that the corrosion resistance of the board to be tested is disqualified when the physical defect area is larger than a preset defect tolerance value.
9. The method for evaluating corrosion resistance of a composite plate based on spectral analysis according to claim 8, wherein the defect tolerance value is set based on the resolution of the acquisition equipment and the international composite plate standard.
10. A system for assessing corrosion resistance of a composite panel based on spectroscopic analysis, comprising a processor and a memory, the memory storing computer program instructions which, when executed by the processor, implement a method for assessing corrosion resistance of a composite panel based on spectroscopic analysis according to any one of claims 1 to 9.

Description

Method and system for evaluating corrosion resistance of composite board based on spectrum analysis Technical Field The invention relates to the field of multispectral imaging analysis and industrial automation control, in particular to a method and a system for evaluating corrosion resistance of a composite board based on spectral analysis. Background The double-metal composite plate is commonly applied to the extreme working environments such as petrochemical containers, ocean engineering platforms, nuclear power heat exchangers and the like because of excellent corrosion resistance and structural strength, is usually manufactured by adopting explosion welding or hot rolling technology, and is subjected to high-strength physical leveling treatment by a large-scale multi-roller leveler in order to eliminate huge residual stress and ensure the flatness of the plate surface after the composite is finished; However, the necessary machining process brings great challenges to the corrosion resistance evaluation of the composite board, and the strong rolling can generate micron-sized anisotropic press-induced textures or micro-roll marks on the surface of the metal coating, so that the physical textures can lead to strong diffuse reflection and scattering of incident light to cause obvious attenuation of local reflected light intensity from the optical perspective; The traditional colorimetric method or gray threshold algorithm judges defects only through illumination intensity change, and cannot distinguish physical light intensity attenuation caused by surface roughness and chemical light intensity attenuation caused by oxidation corrosion from physical mechanisms, so that a common industry pain point is caused, when harmless physical indentations or processing textures exist on the surface of a plate, the traditional method often misjudges the plate as serious corrosion points or surface pollution, extremely high misinformation rate and unnecessary reworking and grinding are caused, the production efficiency is seriously affected, and in addition, the traditional electrochemical probe detection method is accurate, but belongs to contact offline detection, and cannot meet the requirement of realizing full-coverage online evaluation of a high-speed continuous production line. Disclosure of Invention In order to solve the problem that the physical texture interference and chemical corrosion characteristics of the surface of the composite board cannot be analyzed efficiently in real time in the prior art, the invention provides a method and a system for evaluating the corrosion resistance of the composite board based on spectrum analysis. In a first aspect, the invention provides a method for evaluating corrosion resistance of a composite board based on spectrum analysis, which adopts the following technical scheme: The method comprises the steps of configuring a multispectral imaging unit, synchronously collecting spectral response data of each detection point on the surface of a plate to be detected in a first reference wave band, a second reference wave band and a characteristic wave band, preprocessing the spectral response data to obtain the reflectivity data of the detection point in the first reference wave band, the second reference wave band and the characteristic wave band, calculating a nonlinear attenuation factor of the detection point by utilizing the logarithmic difference ratio of the reflectivity data of the detection point in the first reference wave band and the reflectivity data of the detection point in the first reference wave band based on a preset power law model, constructing theoretical reference reflectivity of the detection point in the characteristic wave band under the condition that physical texture interference exists only, calculating the logarithmic residual error of the reflectivity data of the detection point in the characteristic wave band and the theoretical reference reflectivity, and evaluating the corrosion resistance of the plate to be detected by utilizing a preset threshold based on the logarithmic residual error. According to the invention, the theoretical reference reflectivity of the characteristic wave band under the pure physical texture interference is constructed by collecting multi-band data and calculating the nonlinear attenuation factor by utilizing the logarithmic difference ratio, so that the logarithmic residual error is calculated, the system can accurately distinguish the physical texture interference, and only the spectrum absorption characteristic caused by the change of chemical components is reserved, thereby effectively solving the problems that the physical defect cannot be distinguished from the chemical defect and the false alarm rate is high in the traditional optical detection. Further, the first reference wave band and the second reference wave band are selected from the spectrum interval of the passivation layer of the metal surface, wherein